01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
02 - Bring a large pot of salted water to a boil. Cook elbow macaroni until al dente according to package instructions. Drain and set aside.
03 - Melt 4 tablespoons unsalted butter in a large saucepan over medium heat. Whisk in all-purpose flour and cook for 1 to 2 minutes until bubbling but not browned.
04 - Gradually whisk in whole milk and heavy cream, stirring constantly until thickened, about 5 minutes. Add buffalo wing sauce and softened cream cheese, stirring until smooth.
05 - Stir in shredded cheddar, Monterey Jack, blue cheese (if using), garlic powder, onion powder, salt, and black pepper. Mix thoroughly until all cheese is melted and sauce is smooth.
06 - Add shredded chicken and cooked macaroni to the sauce. Fold together until evenly coated and fully incorporated.
07 - Pour the macaroni mixture into the prepared baking dish, spreading out evenly.
08 - Mix panko breadcrumbs and melted butter in a small bowl. Sprinkle mixture evenly over the macaroni.
09 - Bake for 20 to 25 minutes until surface is golden and sauce bubbles along the edges.
10 - Garnish with chopped scallions, if desired. Serve hot.